Method and apparatus for cutting or punching sheet material



p 3, 1946- H. H. MOHAUPT 2,407,093

METHOD AND APPARATUS FOR CUTTING OR PUNGHING SHEET MATERIAL Filed May21, 1942 H. H. Mo/mupf,

13 w, r W

Patented Sept. 3, 1945 METHOD AND APPARATUS FOR CUTTING OR PUNCHINGSHEET MATERIAL 0., assignor Henry H. Mohaupt, Washington, D.

to Societe Anonyme de Gestion et dExploitation de Brevets, SwitzerlandApplication May 21, 1942, Serial No. 443,958 I 15 Claims. (01. 164-45)This invention relates to a simple and practical method and apparatusfor cutting or punch ing sheet or plate material, usually of a ferrouscharacter such as iron or steel.

One of the objects of the present invention is to provide an improvedrelatively small, compact and self-contained article especially adaptedfor cutting or punching holes in sheet metal.

A further object is to provide an article of the above character whichmay be inexpensively manufactured and assembled, andwhich will bereliable and safein use and operation in proper hands.

A further object is to provide an article of the above characterrequiring little or no external means for operating the same at theplace desired.

A further object is to provide an improved method of quickly cutting orpunching holes in sheet metal or the like.

Other objects will be in part obvious and in part hereinafter pointedout in connection with the following analysis of this invention whereinis illustrated an embodiment of the invention in detail.

In the drawing:

Fig. 1 is a semi-diagrammatic perspective view of the device inoperative position upon a sheet of material to be punched;

Fig. 2 is a vertical longitudinal sectional view of the complete device;and

Fig. 3 is a sectional plan view taken substantially on the line 3-3 ofFig. 2 with. parts removed for the sake of clearness.

Referring now to the drawing in detail, 5 indicates diagrammatically asheet of material through which a hole is to be punched or cut by meansof the device shown positioned thereon or in section in Fig. 2. Thisdevice comprises a con- 7 tainer 6 which, for cheapness and simplicityof manufacture, is preferably made cylindrical in form with asubstantially smooth unobstructed inner surface, having a heightslightly greater than its diameter. While shown. cylindrical, it ofcourse could be a polygon of any desired number of sides, but suchconstruction is less desirable because of the dimculty of manufacture.

Centrally disposed within this cylinder is a guide member I which may bea solid bar or a tube as desired, which is concentrically disposed withrelation to the container 5 and is for the purpose of positioning andguiding a cutter or punch 8. This cutter or punch as herein shown isannular in plan view and V-shaped on any radius,- the open part of the vfacing downwardly with relation to the other parts when in the positionshown in Figs. 1 or 2. This cutter or punch 8 is of any suitable metal,and may be mild steel, which may be easily and quickly deformed andcollapsed under'the tremendous pressure, heat and action of theexplosive indicated at H! and positioned in the upper part ofthecontainer 6. The'explosive, which may be of any suitable kind, ispreferably a relatively small quantity of TNT, or any other powerfulexplosive, which is detonated or ignited by any suitable means such as adetonator or cap I The term detonating herein used in the specificationand claims is to be construed broadly as including any means or methodof initiating the action of the explosive within the container.

The upper and lower ends of the container 6 may be closed, if desired,as by means of thin cover plates l2 and I3. These can be of fiber orvery thin sheet metal and are used primarily to protect the explosiveagainst moisture and displacement.

It will be noted particularly that the cutter or punch 8 has africtional fit with respect to the inner wall of the container 6 and theguide 1 and in certain cases may be held in place by its adhesion to theexplosive Ill placed thereabove, which in certain cases is melted andeither poured in the top, or the container may be inverted and, whilethe explosive is still in a semi-plastic condition, the cylinder I andcutter 8 may be pressed downwardly into the semi-molten or plastic mass.Of course, if desired shear pins or the like, such as indicated at 9 maybe used in order to prevent relative movement of the parts if handledroughly.

This cutter 8 for the size hereinafter described, is preferably spacedfrom the botto T3 of the container 6 a distance substantially equal tothe diameter of the case and, being held in position largely by itsfrictional engagement with its coacting parts, is otherwise free tomove. downwardly with respect to the smooth substantially unobstructedinner surface of the container. However, when the explosive charge isdetonated,

the extremely rapid formation of the gases forces the cutter downwardlyat very high speed and at the same time causes the two sides M of thevring to move into intimate engagement. The intense heat generated lially fuses the two sides of the V into one solid, constituting asubstantial. cutting or pimching tool. The cutter thus formed thereby isdriven downwardly against the plate 5 at tremendous speed and greatforce and will by reason of items and inertia instantly ,cutor'punchanopenmg in the plate 5, conforming to'the shape of the cutterwhen the. relative size of the device and, thickness of the plate 1 willpermit. It is'to be noted, however, that the diameter of the hole isactually a little larger thanthe diameter of the container, this beingdue to an outward movement of the cutter and expansion of the bottom ofthe container.

The cutter being of concave ring form as herein shown cuts a circularopening in the plate and the central disc falls clear on operation. Thusthe cutter is far more effective and efilcient in penetrating qualitiesthan were the explosive force to be applied to a solid punch acting onthe entire area of the opening to be out.

In other words, if the container G'is, say, four inches in insidediameter, the cutter 8 should be about four inches from the bottom andwill punch an opening or circle through a mild steel plate about inch inthickness and about 4% inches in diameter. Accordingly, the size of thecontainer may be selected according to the thickness of the plate andthe hole to be punched. The

amount of explosive may be varied as desired.

Thus a four inch hole on a. quarter inch stock requires less explosive.

Itfrequently happens in engineering, mining and construction problems,as well as in other cases, that it is necessary to quickly force anopening through a metal plate or the like, when an acetylene torch orboring machine, or other complicated apparatus, is not available.

The present device is directed to a complete, compact and self-containedmechanism which may be easily and quickly conveyed, placed or positionedwith respect to the plate to be perforated and actuated to accomplishthe penetration, all in a very short space of time. The action of thedevice-is limited to a very specific zone of the obstacle. By way ofexample, a building may be on fire and sections of the buildingprotected from other sections by means of flat steel firedoors either inthe walls or floor which are possibly locked. or otherwise securedagainst movement. Assuming that firemen desire to get a stream of waterto such burning part of the building, or even through the floor of thebuilding, one of these small, portable, self-contained mechanisms, saythree or four inches in diameter, may be placed against the sheetmaterial to be perforated and ignited by a fuse, detonator or even aflashlight battery I5, to almost instantly cut or punch the desiredhole'thro-ugh the door or floor, after which a hose could Ire insertedthrough the opening and the desired results accomplished. Containers ofchemical substances canalso be pushed or projected through the aperturethus produced.

It is thus seen that the present invention contemplates a simple andpractical mechanism as well as a. method for quickly cutting or punchingholes through sheet material and is well adapted to accomplish, amongothers, all of the objects and advantages herein set forth.

In using such terms as upper, lower, "bottom, etc., these are to beinterpreted as being relative or in relation to the drawings showing oneof various possible embodiments or applications. Obviously the-devicecould be applied to a vertical surface such as a sheet metal door or thelike.

As many changes could be made in carrying out the above constructionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawing shall be inierpreted as sense.

I claim: I

1. A self-contained cutter or punch for sheet material comprising acontainer adapted to be positioned adjacent the plate to be cut orpunched, a collapsible concave tool within the container spaced from theplate a material distance, an explosive within the container and on theother side of said tool with respect to the plate whereby, on detonatingthe explosive, the tool is freed from the container by collapsing itssides and driven into said sheet.

2. A cutter or punch as set forth in claim 1, in which the tool isV-shaped in cross-section.

illustrative and not in a limiting 3. A cutter or punch as set forth inclaim 1, in

which said tool is of ring-form and V-shaped in cross-section on anyradius of the ring.

4. A cutter or punch as set forth in claim 1, in which said tool is ofring-form and V-shaped in cross-section on any radius of the ring, theopen end of the V facing the plate to be perforated and the point of theV adjacent the explosive.

I 5. A substantially cylindrical container of a height slightly inexcess of its diameter, the half adjacent the plate to be out being freeand unobstructed, a tool inthe container positioned near the middle ofthe container and held in position largely by frictional engagement withthe container, and an explosive in the container between the tool andthe outer end of thecontainer, said tool being V-shaped incross-section.

6. A substantially cylindrical container of a height slightly in excessof its diameter, the half adjacent the plate to be out being free andunobstructed, a tool in the container positioned near the middle of thecontainer and held in position largely by frictional engagement with thecontainer, and an explosive in the container between the tool and theouter end of the container, said tool being annular in form and V-shapedin cross-section on any radius whereby on detonating th explosive thetool is deformed by bringing the sides of the V into contact and freedfrom contact with the sides of the container and driven through theplate.

7. A container of a height or length slightly in excess of itstransverse dimension and having a smooth internal surface, a centrallydisposed guide within said container, an annular tool positioned in thecontainer and about the guide and held in position largely by itsfrictional contact with the guide and the inner surface of the container and spaced from the plate to be cut a distance substantiallyequal to the diameter of the container, and an explosive adjacent thetool and on'its opposite side from the plate to be perforated whereby ondetonating the explosive the tool is deformed and freed from contactwith the sides of the container and driven a a cutting ring into theplate.

8. An apparatus as set forth in claim 7 in which the tool is V-shaped incross-section taken on any radius.

9. An apparatus as set forth in claim 7 in which the tool is V-shaped incross-section taken on any radiu and the open end of the V faces theplate to be cut.

10. A device of the character described comprising a substantiallycylindrical container, the lower part of which provides a free andunobstructed bore, a cutting tool within the bore and positioned amaterial distance up said unobstructed bore, said cutting toolcomprising a concave member facing downwardly, and explosive 11. Adevice of the character set forth in claim 10 in which the cutter is ofannular form to make a circular opening and disc-shaped cutting.

12. A device of the character described, comprising a substantiallycylindrical container with an inverted concave cutting tool positionedtherein and embedded in and held in position by an explosive on itsupper side, the lower part of said container providing a free andunobstructed bore for said tool, and means for detonating said explosivethereby to drive said cutter downwardly with great velocity andsimultaneously fuse and collapse its sides to form a substantially solidcutting member.

13. A device a set forth in claim 12 in which the cutter is of ring formthereby to make a circular cutting with a central solid disc.

14. The herein described tool for cutting or punching an opening insheetmetal or the like comprising a container having an explosive anddetonator, and a collapsible concave cutter or punch ring in theproximity of the sheet to be perforated, with the concave surface of thecutter facing the sheet metal and spaced at a material distancetherefrom, whereby on detonating the explosive the sides of themtool arecollapsed and fused into substantially o solid mass with a sharp cuttingedge adapted to be driven through the sheet to be cut or punched.

15. The herein described method of cutting or punching out a disc insheet metal or the like, comprising the steps of positioning a.container having an explosive'and a collapsible inverted concave cutterring adjacent the plate to be cut with the cutter ring freely spaced amaterial distance therefrom, and detonating the explosive to collapsethe ring and fuse the sides of the concave cutter ring by the heat ofexplosion into one substantially solid mass to drive the ring throughthe plate and to cut a disc out of the plate.

HENRY H. MOHAUPT.

